You can't just get a bulldozer and start knocking down trees and move dirt around.Usually, before a person buys land they make an Offer To Purchase and the closing of escrow is contingent upon getting building permits and your building department's approval to develop the property.

Not to mention things like utilities, permits, materials and people not showing up.

Depends on:- Location- Types of contractors you use- How the project is managed (GC or Self)- Level of Finishes- Time of Year- Permit and Impact Fees- Your Negotiating SkillsLooks like you're in Atlanta -- you're likely somewhere between $80/sf and $150/sf, depending on the things above. 

No need to recreate the wheel or pay a lawyer. 

Bit of background - The property is in a commercial area and I believe at one point in time was a hair salon.Given this is my first rental and my inexperience I reached out to a couple contractors and one of them told me to start at the permitting and zoning office.

NJ uses the same codes across every town and the paper work is pretty much the same for permits etc.

Ironically, it actually discouraged me from building a permitted ADU and opting for a nonpermitted basement ADU for au-pair quarters and later on airbnb (STR not allowed for permitted ADUs/duplexes etc) which seems to be a better return on investment vs. long term renter if living close-in. 

In my city not only do you need a permit but every household within a certain distance of your building has to sign off on it.  

Lastly, you could study permit data to get a better idea of how the relationship between supply and demand is trending in your target market. 

Both inspection reports called out a long list of repairs, although the previous inspection had more issues that I addressed before the new buyer's inspection.Buyer's claim: buyer send me the attached letter claiming that he bought the house because he thought it was renovated well and now he has to spend money on renovations and repairing damages resulting from the unpermitted workMy claim:The buyer had never asked for permits and neither me or my realtor ever claimed permits were pulled for any work.